The received wisdom that last-minute flights are always expensive is only half true. It holds on business routes into Monday and out of Thursday, where carriers deliberately reserve inventory for late corporate booking at high fares. It breaks down on leisure routes, where an airline facing an unsold cabin three days out would rather sell the seat cheaply than fly it empty. CheapOair's last-minute view surfaces those unsold-inventory fares across hundreds of carriers. The practical rule is flexibility on the airport, not just the date — a fare that looks bad from your primary airport can look very different from the secondary one an hour away. Runs through 31 December.